title: Effect of vitamin D supplementation on antibiotic use: a randomized controlled trial.
abstract: BACKGROUND
  Observational data suggested that supplementation with vitamin D could reduce risk of infection, but trial data are inconsistent.
  
  
  OBJECTIVE
  We aimed to examine the effect of oral vitamin D supplementation on antibiotic use.
  
  
  METHODS
  We conducted a post hoc analysis of data from pilot D-Health, which is a randomized trial carried out in a general community setting between October 2010 and February 2012. A total of 644 Australian residents aged 60-84 y were randomly assigned to receive monthly doses of a placebo (n = 214) or 30,000 (n = 215) or 60,000 (n = 215) IU oral cholecalciferol for ≤12 mo. Antibiotics prescribed during the intervention period were ascertained by linkage with pharmacy records through the national health insurance scheme (Medicare Australia).
  
  
  RESULTS
  People who were randomly assigned 60,000 IU cholecalciferol had nonsignificant 28% lower risk of having antibiotics prescribed at least once than did people in the placebo group (RR: 0.72; 95% CI: 0.48, 1.07). In analyses stratified by age, in subjects aged ≥70 y, there was a significant reduction in antibiotic use in the high-dose vitamin D compared with placebo groups (RR: 0.53; 95% CI: 0.32, 0.90), whereas there was no effect in participants aged <70 y (RR: 1.07; 95% CI: 0.58, 1.97) (P-interaction = 0.1).
  
  
  CONCLUSIONS
  Although this study was a post hoc analysis and statistically nonsignificant, this trial lends some support to the hypothesis that supplementation with 60,000 IU vitamin D/mo is associated with lower risk of infection, particularly in older adults. The trial was registered at the Australian New Zealand Clinical Trials Registry (anzctr.org.au) as ACTRN12609001063202.
authors.affiliation: Population Health Department, Queensland Institute of Medical Research, Brisbane, Queensland, Australia (BT, DCW, PMW, and REN); the Centre for Research Excellence in Sun and Health, Queensland University of Technology, Kelvin Grove, Queensland, Australia (BT, MGK, DCW, and REN); the School of Population Health, University of Queensland, Brisbane, Queensland, Australia (JCvdP); the Sydney School of Public Health (BKA) and the National Health and Medical Research Council of Australia Clinical Trials Centre, Sydney Medical School (VG), University of Sydney, Camperdown, New South Wales, Australia; Northwest Academic Centre, University of Melbourne, and Western Health, Melbourne, Victoria, Australia (PRE); the School of Population Health, University of Melbourne, Parkville, Victoria, Australia (DRE); the AusSun Research Laboratory, Queensland University of Technology, Kelvin Grove, Queensland, Australia (MGK); and the Menzies Research Institute Tasmania, Hobart, Tasmania, Australia (AV).
authors.forename: Bich
authors.initials: B
authors.lastname: Tran
authors.forename: Bruce K
authors.initials: BK
authors.lastname: Armstrong
authors.forename: Peter R
authors.initials: PR
authors.lastname: Ebeling
authors.forename: Dallas R
authors.initials: DR
authors.lastname: English
authors.forename: Michael G
authors.initials: MG
authors.lastname: Kimlin
authors.forename: Jolieke C
authors.initials: JC
authors.lastname: van der Pols
authors.forename: Alison
authors.initials: A
authors.lastname: Venn
authors.forename: Val
authors.initials: V
authors.lastname: Gebski
authors.forename: David C
authors.initials: DC
authors.lastname: Whiteman
authors.forename: Penelope M
authors.initials: PM
authors.lastname: Webb
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Neale
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D002762:Cholecalciferol / Q000008:administration & dosage*; D019587:Dietary Supplements; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009520:New Zealand; D010865:Pilot Projects; D012141:Respiratory Tract Infections / Q000188:drug therapy / Q000453:epidemiology*; D016896:Treatment Outcome; D014815:Vitamins / Q000008:administration & dosage
chemical_list: D000900:Anti-Bacterial Agents; D014815:Vitamins; D002762:Cholecalciferol